Some medicaments are injected as heavy soluble crystals or particles suspended in a solvent. When injected the heavy soluble medicine is during time dissolved by the tissue liquid. Instead of suspending or dissolving the medicine in a solvent the dry medicine may be pressed to a small needle shaped peg which can be inserted into the tissue from where it is during time dissolved by the tissue liquid.
From U.S. Pat. No. 5,542,920 is known a device by which a peg stored in a barrel which is provided in a housing and from which said peg can be pressed into the skin by a plunger which can be passed into the barrel by pressing a button. Alternatively the peg can be shot into the skin by a spring or by applying a gas pressure behind the peg in the barrel.
When the peg is pressed into the skin by a plunger which is pressed into the barrel from one end thereof whereas the other end of the barrel is pressed against the skin where the insertion is wanted, the plunger must be pressed to a position where its end facing the peg is passed some millimetres into the skin to ensure that the peg is inserted to a subcutaneous position. Thereafter it is wanted to have the plunger drawn back into the barrel so that the end of the plunger, which may have been contaminated by the insertion, is hidden in the barrel. This may be obtained by providing a spring between the housing and the button by which the plunger is pressed into the barrel. By the insertion movement of the button this spring is compressed and when the button is released said spring will press the button back and this way draw the plunger back from its peg insertion position leaving the peg subcutaneously inserted.
It is an objective of the invention to provide a small handy device by which a solid medicine peg may be automatically inserted.